The present invention relates to a radial-piston pump, particularly for internal combustion engine fuel.
EP-A2-0 299 337 relates to a radial-piston pump wherein the intake valve of each cylinder is coaxial with the cylinder, and the valve seat is formed in the head closing the cylinder. Fuel is supplied to the intake valve by a channel comprising various portions located in the head, the cylinder and the shell of the pump. A first of these portions consists of a hole in the head, and is coaxial with the cylinder. Another consists of a transverse hole, perpendicular to the cylinder axis, and terminates inside the first portion, so that the hole must be formed externally in the head and plugged outwards. A third portion of the intake channel is parallel to the cylinder axis and, through the cylinder, extends inside the head and into the transverse hole.
The cylinder head of the above known pump is normally screwed to the shell of the pump, so that it must be made of relatively soft, flexible material, whereas the valve seat must be made of relatively hard material to prevent premature wear. If the valve seat is located on the head, this must be locally hardened and is thus subject to breakage. Finally, the valves of the above known pump are located in large-volume, high-cost construction parts, thus resulting in high-cost repair in the event of valve failure.